ConfBridge disconnect issue. UDP or TCP?

We have an ongoing issue where handsets in a remote office, connected over a VPN to the FreePBX install disconnect conferences after 15 minutes. The system is configured to use app_confbridge. FreePBX is 10.13.66-16 and we’re running Asterisk 11.23.1

The only timeout setting I can find in the firewall that is at 9000 is the tcp-established value. I’ve bumped it to 18000, but it would be helpful to know if app_confbridge uses UDP or TCP.


Check your logs.

Your phones are probably connecting with UDP, and there is a setting that I just can’t find that should help with this.

It might be “reinvite=” in your SIP settings, but don’t quote me.

On the router on that far end I changed the following:
UDP Connect Timeout from 90 to 180
UDP Deliver Timeout from 300 to 600
TCP Established Timeout from 9000 to 18000

The latter was the only session related setting I could find that was at 15 minutes (9000 seconds), which is when the conferences were disconnecting. The client reports that a test conference did not disconnect after 15 minutes, but they did not let it run 30 (the new TCP timeout).

Check this thread out. and see if that helps at all. The channel may be collapsing because of RTP packets not being acknowledged after the RTP Session timeout.